Contamination or yeast reactivation?

pliftkl · 09-26-2006, 05:17 AM

I'm in the process of brewing my third batch. For this batch, I chose an Imperial Pale Ale from Austin Homebrew Supply. This is my first attempt at a beer with a higher alcohol content. In my previous brews, I had a fruity taste that I think was a result of the high temperatures of my Texas home. For this brew, I figured I'd try to beat the heat by letting the primary sit in a half-full tub of cold water. The airlock showed significant activity for the first 4 days. Yesterday, I moved the primary out of the tub and set it on a counter, with the intention of letting it settle for a few hours before transfering to the secondary. I didn't get around to making the transfer right away, and had to take care of that this evening. However, when I opened the lid, I saw that there seemed to be some white things floating on the top. I didn't have anything floating on the top on either of my previous batches. I went ahead and transferred to the secondary.

Could the fact that I removed the primary from the tub into a higher temperature have "reactivated" the yeast and caused the white buildup on the surface?

If the beer is contaminated, how will I know? Will this just be evidenced by bad tastes after I've bottled?

The normal temperature of my house is 80 at night and up to 84 during the day.

**Walker** · 09-26-2006, 05:48 AM

what did the stuff look like on top of your beer?

Brewsmith · 09-26-2006, 05:54 AM

If you moved the fermenter, you can cause built up CO2 to come out of solution. It may have just brought up some yeast from the bottom. If it was just a few chunks, you're probably fine. If it was an entire layer across the top, you may have racked too soon. For bigger beers, try to leave the primary alone for at least a week just to make sure they're done. The extra time on the yeast is not a bad thing for flavors either.

Blender · 09-26-2006, 06:09 AM

Take Brewsmith's advice and let your next beer ferment out for a good 7-10 days. If what you saw was tiny,tiny bubbles that may have looked like white stuff then it was probably CO2 clinging to yeast bits. Taste it before bottling and you will likely know if it is bad.

pliftkl · 09-26-2006, 06:24 AM

Quote:

Originally Posted by Walker-san

what did the stuff look like on top of your beer?

It looked a lot like the crud that normally clings to the edges of my primary after fermentation, but it was a much whiter color.

Brewsmith · 09-26-2006, 06:25 AM

How much was there?

pliftkl · 09-26-2006, 06:27 AM

Quote:

Originally Posted by Blender

Take Brewsmith's advice and let your next beer ferment out for a good 7-10 days. If what you saw was tiny,tiny bubbles that may have looked like white stuff then it was probably CO2 clinging to yeast bits. Taste it before bottling and you will likely know if it is bad.

It had actually been 8 days in the primary before I did this (well, 7 to pull it out of the water).

What I found disturbing was the color, which seemed so much different (whiter) than anything else I'd ever seen in my beer. The problem is, I'm not experienced enough to have seen much of anything in my beer, so personal experience doesn't count for much!

Brewsmith · 09-26-2006, 06:30 AM

My guess is that you're fine, just some yeast that floated up to the top. The stuff on the sides has trub and hop particles in it that can give it a brown to green color. The yeast itself is more of an off-white color.

pliftkl · 09-26-2006, 06:32 AM

Quote:

Originally Posted by Brewsmith

How much was there?

Actually, not too much. It was really just a few "chunks". If I had to guesstimate, I'd guess that it covered less than 5% of the surface of the beer, though there did seem to be something on the surface of the beer that looked "oily" for lack of a better word.

I'm kicking myself for not taking photos when I had the chance.

I'm really hoping this is just something related to the change in temperature. It's 80 in my house right now, which was probably a big jump from the water cooled primary. My wife is from south-east asia, and when I turn the AC below 80, she thinks I'm trying to freeze her out. Given that she's otherwise perfect, I'm willing to accept this minor flaw and try to find a way to brew at higher temperatures...

pliftkl · 09-26-2006, 06:33 AM

Quote:

Originally Posted by Brewsmith

My guess is that you're fine, just some yeast that floated up to the top. The stuff on the sides has trub and hop particles in it that can give it a brown to green color. [bold]The yeast itself is more of an off-white color.[/bold]

Thanks! That's something of a relief. I'd invested a lot of effort in keeping this beer cool during primary fermentation, and I'd hate to have to toss this.